1. Field of the Invention
The subject invention relates to data processing and, more specifically, to the processing of data including a recurring characteristic mark or error which during further processing is to be acted on or eliminated.
2. Description of the Prior Art
Despite the rapid advance of electronic data processing and computer technology in recent years, there persists a need for a more rapid recognition of recurring characteristic marks or errors. For instance, a rapid recognition of delimiter marks is required in many instances where this is necessary to an identification of word or line lengths. Similarly, a rapid recognition of shift codes is required where data or its display is to be shifted during data processing. A rapid recognition of recurring errors is also required in error elimination routines.
By way of example, and not by way of limitation, reference may be had to computer output microfilm (COM) equipment. Most computer installations have many applications for which there is a very large printout to be used for reference purposes. Such printouts are bulky, take large storage space and are difficult to access. By the use of COM equipment, wherein data is displayed on a cathode ray tube (CRT) the screen of which is exposed to microfilm, a microfilm copy of the output either as a roll or as a microfiche is produced. The speed of recording is many times faster than printing and additional microfilm copies may be made at very low cost.
On the other hand, the attainable or potential rapid speed of recording requires a very rapid recognition of record marks which delimit each line, for a rapid line-by-line display of the output. By way of further example, a rapid recognition of shift marks is required for frequent shifts in the display between lower and upper case representation.
A similar need exists in applications wherein a recurring error is to be detected and rapidly eliminated.
So far the emphasis in the area under consideration has been on the improvement of programing or software. In brief, programs and software were perfected to effect a character-by-character search of processed data to detect characteristic marks therein. Upon detection of each mark, the particular data shifting process had to be interrupted so that the detected mark could be acted upon. The result was not only an extensive complication of the computer program, but also a significant reduction of the overall data processing speed because of the time required to effect the various subroutines and because of the delays brought about by the latter frequent interruptions.